Electromagnetic waves have been used in various applications to supply energy to objects. In the case of radio frequency (RF) radiation, for example, electromagnetic energy may be supplied using a magnetron, which is typically tuned to a single frequency for supplying electromagnetic energy only at that frequency. One example of a commonly used device for supplying electromagnetic energy is a microwave oven. Typical microwave ovens supply electromagnetic energy at or about a single frequency of 2.45 GHz.
Traditional methods for processing items using electromagnetic energy typically involve pre-set or user-set cooking times and power levels. For example, when a user desires to cook a frozen pizza in a microwave oven, the user must either manually sets the power level and cook time or, in some instances, the user may select a pre-set time and power setting.